Many buildings are equipped with emergency alarm systems, detecting fire, burglary or other types of events. Such alarm systems can be more or less sophisticated, ranging from standalone fire alarm units to advanced monitoring systems with surveillance cameras analysing images to find potentially hazardous items and reporting such events to a security operator.
Different types of emergency alarm systems for buildings have in common that they include some kind of detector and also some way of indicating that the detector has been triggered. In the example of the standalone fire alarm unit, the detector could be a photoelectric detector or an ionization detector. When smoke particles enter the detector, the alarm unit is set off and a loud bell or horn is sounded, providing an indication of the detection. In case of the advanced monitoring systems, the camera can be seen as a detector, and the indication of the detection can be in the form of a message to the security operator. Another example is detectors in the form of microphones connected to software or hardware analysing captured sounds and comparing to typical profiles for sounds indicating an emergency, such as explosions or gunshots.
While all these emergency alarm systems have many advantages, there are also some disadvantages involved. In case of a standalone detector, it has the obvious disadvantage of not being noticed in all parts of a large building. This can be countered by including several standalone units, or by connecting the units to one another, such that if one of the units makes a detection, all the units will be triggered. In some cases, a detection by any of the units will also cause an automatic alarm to be sent to an alarm central alerting emergency personnel. However, in many cases, there is no indication of where in the building the detection was made.
Even if sophistication is added to the system by including individually addressable units, with position information logged for each unit, it may still be difficult to relay such position information to the emergency personnel in a prompt manner. This means that when the emergency personnel arrive at the site, it is often difficult for them to quickly understand where in the building they should focus their initial efforts, and valuable time may be wasted trying to find the location or locations of the emergency in the building. In addition, the site of the emergency may move within the building, such as when a weapon is fired at a number of different locations in the building. This especially a problem in case of large multi-level buildings such as schools or large apartment or office buildings.
Even if the position information of each unit being triggered may be available to a security operator, it may still be difficult for the emergency personnel to retrieve and use the information at the site of the emergency. There may e.g. be a lack of technical equipment for accessing the information, or logical access rights to the monitoring system may be missing. This could e.g. be the case when emergency personnel from another district is responding to the alarm. Again, valuable time may be wasted trying to locate the source of an alarm in a large building.
In addition, in case of an emergency spreading or moving through a building, not only the position of the triggered alarm unit, but also the time line is important. One example is that in the case of gas explosions in a large building it is useful to know if the site of the explosions is travelling in a certain direction. The same is true for gunshot detectors, where it is highly important to be able to understand where the shots have been heard, since there may be wounded people needing immediate help. It is also very important to know where the shots were last heard, so that the source of the gunshots may be located and stopped.
Hence, there is a need for an improved emergency alarm system where alarm location information can be quickly and easily transmitted to emergency personnel arriving at a large building.